Fluid heating appliance

ABSTRACT

A coffeemaker generally includes a reservoir and a flow control system for regulating a flow of water from the reservoir. The flow control system has a thin-film heating element that defines at least a portion of a heating conduit in which water is heated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/980,468 filed on Apr. 16, 2014, which is incorporated by referenceherein in its entirety.

BACKGROUND

The present invention relates generally to fluid heating appliances and,more particularly, to an appliance for brewing a beverage (e.g., acoffeemaker).

Many conventional coffeemakers have a water reservoir, a showerhead, anda flow control system. The flow control system includes an arrangementof tubes and a pump for generating a flow of water from the reservoir tothe showerhead through the tubes. At least some conventionalcoffeemakers also include a calrod-type heating device that heats thewater as the water flows from the reservoir to the showerhead. However,it can be difficult to regulate water temperature with calrod-typeheating devices, not to mention the less than desirable heat-up time andbulkiness of calrod-type heating devices.

It would be useful, therefore, to provide a coffeemaker with a smallerheating device that enables water to be heated quicker and to a moreprecise temperature.

SUMMARY

In one embodiment, a coffeemaker generally comprises a reservoir and aflow control system for regulating a flow of water from the reservoir.The flow control system includes a thin-film heating element thatdefines at least a portion of a heating conduit in which water isheated.

In another embodiment, a coffeemaker generally comprises a reservoir, ashowerhead, and a flow control system for regulating a flow of waterfrom the reservoir to the showerhead. The flow control system includes athin-film heating element that defines a heating conduit in which wateris heated. The flow control system further includes a check valvedisposed between the reservoir and the heating element, and a flowcontrol valve disposed between the heating element and the showerhead.

In yet another embodiment, a terminal unit for a heating device having apair of tubular, thin-film heating elements generally comprises a pairof ring-shaped terminals each sized to wrap around one of the heatingelements. The terminal unit also includes a bus bar extending betweenthe ring-shaped terminals to electrically connect the ring-shapedterminals to one another.

BRIEF DESCRIPTION

FIG. 1 is a perspective view of one embodiment of a fluid heatingappliance;

FIG. 2 is a side view of the fluid heating appliance of FIG. 1;

FIG. 3 is the side view of FIG. 2 with a side panel of the appliancehousing removed;

FIG. 4 is a cross-sectional view of the fluid heating appliance of FIG.2 taken along plane 4-4 of FIG. 2;

FIG. 5 is a perspective view of a heating device of the fluid heatingappliance of FIG. 4;

FIG. 6 is a perspective view of a terminal unit of the heating device ofFIG. 5;

FIG. 7 is a cross-sectional view of a heating element of the heatingdevice of FIG. 5;

FIG. 8 is an enlarged portion of the cross-sectional view of FIG. 7taken within area 8;

FIG. 9 is a schematic illustration of an embodiment of a flow controlsystem for use in the fluid heating appliance of FIG. 3;

FIG. 10 is a perspective view of an embodiment of a heating device andassociated showerhead for use in the fluid heating appliance of FIG. 3;and

FIG. 11 is a cross-sectional view of the heating device and showerheadof FIG. 10.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DETAILED DESCRIPTION

Referring to the drawings, and in particular to FIGS. 1 and 2, a fluidheating appliance is illustrated in the form of a coffeemaker (indicatedgenerally by the reference numeral 100). It is contemplated that, inother embodiments, the fluid heating appliance may be any suitable typeof appliance that heats fluid (i.e., gas or liquid) for any suitablepurpose without departing from the scope of this invention (e.g., thefluid heating appliance may be a hot water dispenser in someembodiments).

The illustrated coffeemaker 100 includes a housing 102, a filter basket104 detachably mounted on (e.g., suspended from) the housing 102, and ahot plate 106 situated beneath the filter basket 104. In this manner,the coffeemaker 100 is configured to receive a carafe (e.g., a coffeepot 108) on the hot plate 106 beneath the filter basket 104 forcontaining a brewed beverage (e.g., coffee) discharged from the filterbasket 104 during a brewing operation.

To enable viewing of internal componentry of the coffeemaker 100 duringits operation, at least one window is provided on the housing 102,namely a pair of opposing first windows 110 and a pair of opposingsecond windows 112 in the illustrated embodiment. In other embodiments,however, the coffeemaker 100 may be configured in any suitable mannerthat facilitates enabling the coffeemaker 100 to heat liquid asdescribed herein (e.g., the coffeemaker 100 may not have the detachablefilter basket 104, the hot plate 106, and/or the windows 110, 112 insome contemplated embodiments).

With reference now to FIG. 3, the illustrated coffeemaker 100 furtherincludes a reservoir 114, a showerhead 116, and a flow control system(indicated generally by reference numeral 118) for regulating a flow ofliquid from the reservoir 114 to the showerhead 116. The reservoir 114is configured to contain a liquid suitable for brewing a beverage (e.g.,water), and the amount of liquid contained within the reservoir 114 isobservable through the first windows 110. The showerhead 116 issituated, at least in part, above the filter basket 104 for dischargingliquid onto a brewable product (e.g., coffee grounds) placed on a filterinside the filter basket 104.

The flow control system 118 includes a pump 120, a holding tank 122, anda heating device (indicated generally by reference numeral 124)connected in flow communication with one another by a suitable networkof conduits. In the illustrated embodiment, the network includes: anupstream conduit 126 which connects the reservoir 114 to the pump 120; acolumn conduit 128 which connects the pump 120 to the holding tank 122;a downstream conduit 130 which connects the holding tank 122 to theheating device 124; and a ventilation conduit 132 which connects theholding tank 122 to the exterior of the housing 102 for ventilating thenetwork to the ambient. Alternatively, the flow control system 118 mayhave any suitable components arranged in any suitable manner thatfacilitates supplying liquid from the reservoir 114 to the heatingdevice 124 (e.g., the flow control system 118 may not include the pump120 and/or the holding tank 122 in some contemplated embodiments, or theflow control system 118 may have a different network of conduits inother embodiments).

As shown in FIGS. 4 and 5, the heating device 124 includes at least onethin-film heating element, namely a first heating element 136 and asecond heating element 138 in the illustrated embodiment. Withoutdeparting from the scope of this invention, the heating device 124 maybe configured with any suitable number of thin-film heating elements(e.g., the heating device 124 may have only one heating element in someembodiments, or the heating device 124 may have more than two heatingelements in other embodiments).

Referring now to FIGS. 7 and 8, each of the heating elements 136, 138 istubular and has a first end 140, a second end 142, and a multi-layerbody 144 extending from the first end 140 to the second end 142. Thebody 144 has a radially inner layer in the form of a substrate 146, anda radially outer layer in the form of an electrically conductivematerial 148 deposited on the substrate 146. As used herein, eachheating element 136, 138 of the heating device 124 is said to be a“thin-film” heating element in the sense that the substrate 146 and theelectrically conductive material 148 have a collective thickness that isonly marginally greater than the thickness of the substrate 146 itself(i.e., the material 148 forms a thin film on the substrate 146).

In the illustrated embodiment, the first heating element 136 and thesecond heating element 138 are substantially identical (i.e., are madein the same manner using the same materials so as to have the sameoverall construction within accepted manufacturing tolerances). Forinstance, the substrate 146 of the heating elements 136, 138 may be aglass substrate (e.g., a borosilicate substrate, a quartz substrate,etc.), and the electrically conductive material 148 of the heatingelements 136, 138 may be a metal oxide material (e.g., a tin oxidematerial). Hence, while only the first heating element 136 is shown inFIGS. 7 and 8, it is understood that the second heating element 138 isconfigured to be substantially identical.

In other embodiments, the heating elements 136, 138 may not besubstantially identical (e.g., the first heating element 136 may haveits substrate 146 made of a first composition, and its electricallyconductive material 148 made of a second composition; whereas the secondheating element 138 may have its substrate 146 made of a thirdcomposition that is different than the first composition, and itselectrically conductive material 148 made from a fourth composition thatis different than the second composition). Alternatively, each heatingelement 136, 138 of the heating device 124 may have its substrate 146and its electrically conductive material 148 made from any suitablecomposition(s) that facilitate enabling the heating element(s) 136, 138to function as described herein.

In the illustrated embodiment, the substrate 146 forms at least asegment of an interior surface 150 of the body 144, and the interiorsurface 150 defines a heating conduit 152 which extends through the body144 from the first end 140 to the second end 142. In an alternativeembodiment, an additional layer of the body 144 (e.g., a coating) may bedisposed on a radially inner side of the substrate 146 such that theadditional layer forms some or all of the interior surface 150.

The electrically conductive material 148, on the other hand, forms atleast a segment of an exterior surface 154 of the body 144. For example,in the illustrated embodiment, the electrically conductive material 148completely covers the radially outer side of the substrate 146, in thesense that the material 148 wraps completely around the substrate 146from near the first end 140 to near the second end 142. In anothercontemplated embodiment, the material 148 may not completely cover theradially outer side of the substrate 146 but, rather, may instead bedeposited on the substrate 146 in any suitable pattern (e.g., thematerial 148 may be deposited in a pattern of circumferentiallyspaced-apart lines, or a grid-like formation, that extends from near thefirst end 140 to near the second end 142).

Referring back to FIGS. 4 and 5, the body 144 (e.g., the substrate 146and the electrically conductive material 148) are substantiallytransparent in the illustrated embodiment, thereby enabling liquidwithin the heating conduit 152 to be viewed from outside of the housing102 through the second windows 112. In this manner, the illustratedcoffeemaker 100 has a light source (e.g., at least one light emittingdiode (LED) 156) for emitting light (e.g., a colored light such as redlight, green light, blue light, etc.) through the heating conduit 152 toilluminate the liquid disposed within the heating conduit 152. Thisenhances the overall aesthetic appeal of the coffeemaker 100 duringoperation (e.g., the LEDs 156 facilitate illuminating bubbles in theliquid when the heating elements 136, 138 heat the liquid and as thebubbles rise through the heating conduit 152). While the illustratedLEDs 156 are disposed near the first ends 140 of the heating elements136, 138 as set forth in more detail below, the LEDs 156 may be disposedat any suitable location(s) in other embodiments. Alternatively, thebody 144 (e.g., the substrate 146 and/or the electrically conductivematerial 148) may be opaque (and the LEDs 156 therefore absent from thecoffeemaker construction) without departing from the scope of thisinvention.

In the illustrated embodiment, the heating elements 136, 138 areoriented substantially parallel to one another and are held inspaced-apart relation via a grommet (or spacer) 158, and the grommet 158engages a bracket 161 of the housing 102 to facilitate stabilizing theheating elements 136, 138 within the housing 102. Moreover, each of theheating elements 136, 138 is attached at its first end 140 to a one-way(or check) valve 162 via a first coupling 164 such that the heatingconduit 152 is in flow communication with the downstream conduit 130across the one-way valve 162. Each of the heating elements 136, 138 isalso attached at its second end 142 to the showerhead 116 via a secondcoupling 166 such that the heating conduit 152 is in flow communicationwith the showerhead 116.

In the illustrated embodiment, the couplings 164, 166 are fabricatedfrom a material that facilitates electrically and thermally isolatingthe heating elements 136, 138 from the one-way valve 162 and theshowerhead 116, respectively (e.g., the couplings 164, 166 may befabricated from a plastic or rubber material). Moreover, the one-wayvalve 162 is substantially transparent in the illustrated embodiment,and the LEDs 156 are mounted beneath the one-way valve 162 on a ledge160 of the housing 102 to emit light through the one-way valve 162 intothe heating conduit 152.

The illustrated heating device 124 further includes a first terminal 168and a second terminal 170 attached to each of the heating elements 136,138. The first terminal 168 is ring-shaped and wraps around the body 144near the first end 140 in electrical contact with the material 148.Similarly, the second terminal 170 is ring-shaped and wraps around thebody 144 near the second end 142 in electrical contact with the material148. In alternative embodiments, the terminals 168, 170 may have anysuitable shape and may be electrically connected to the material 148 ofthe body 144 in any suitable manner that facilitates enabling theheating elements 136, 138 to function as described herein.

Referring now to FIGS. 5 and 6, the first terminals 168 are electricallyconnected to one another via a first bus bar 172 to form a firstterminal unit (indicated generally by reference numeral 174), therebyenabling electrical current to flow from one of the first terminals 168to the other of the first terminals 168 across the first bus bar 172.Similarly, the second terminals 170 are electrically connected to oneanother via a second bus bar 176 to form a second terminal unit(indicated generally by reference numeral 178), thereby enablingelectrical current to flow from one of the second terminals 170 to theother of the second terminals 170 across the second bus bar 176. Becausethe first terminal unit 174 and the second terminal unit 178 aresubstantially identical in the illustrated embodiment, only the firstterminal unit 174 is represented in FIG. 6.

In some contemplated embodiments the first terminals 168 may not beelectrically connected to one another via the first bus bar 172, and thesecond terminals 170 may not be electrically connected to one anothervia the second bus bar 176. Moreover, in other contemplated embodiments,the terminal units 174, 178 may be configured to suit any number ofheating elements (e.g., the first terminal unit 174 may have four firstterminals 168 electrically connected together by the first bus bar 172if the heating device 124 has four heating elements). Alternatively, thematerial 148 may not extend from near the first end 140 to near thesecond end 142, but may instead be limited to a central region of thebody 144 such that the terminals 168, 170 are electrically connected tothe body 144 at the central region of the body 144 rather than near theends 140, 142 of the body 144.

In the illustrated embodiment, each of the terminals 168, 170 and eachof the bus bars 172, 176 have a wire port 180 that facilitateselectrically connecting wires to the terminal units 174, 178. In thismanner, by virtue of the terminals 168, 170 being in electrical contactwith the material 148, the material 148 of each heating element 136, 138is electrically connectable to a suitable power supply (e.g., a batterystowed within the housing 102 or a remote power supply) via the wires.

When electrical current is thereby supplied to each heating element 136,138, the electrical current flows from the first terminal 168 to thesecond terminal 170 across the electrically conductive material 148.Because the material 148 naturally resists the flow of currenttherethrough, the material 148 heats up as a result. Such heating of thematerial 148 causes the substrate 146 to be heated by virtue of thesubstrate 146 being in conductive heat transfer with the material 148.This facilitates heating any fluid (e.g., water) disposed within theheating conduits 152.

In the illustrated embodiment, the electrical current supplied to theelectrically conductive material 148 is regulated by a control unit 182(shown in FIG. 3) disposed within the housing 102. More specifically,the control unit 182 modulates the flow of electrical current from thepower supply through the electrically conductive material 148 duringoperation of the coffeemaker 100 to control the temperature of thesubstrate 146 and, hence, the temperature of the liquid flowing throughthe heating conduits 152.

Optionally, the control unit 182 may be operatively connected to asuitable temperature sensor (e.g., a bimetallic temperature switch 184,shown in FIGS. 3 and 4) for regulating a temperature of the heatingelements 136, 138 (such as, for example, to facilitate preventing theheating elements 136, 138 from overheating if little or no water isinside heating conduits 152). The control unit 182 suitably includes amicrocontroller and a memory for storing instructions to be executed bythe microcontroller when modulating electrical current to the heatingelement(s) 136, 138 in response to a selection by the user.

In one example of operating the coffeemaker 100 to brew coffee, the userpresses a button on an interface of the coffeemaker 100 (or a remoteinterface, such as a wireless device). The control unit 182 responds bysupplying electrical current to the heating elements 136, 138, and theelectrical current flows across the material 148 of each heating element136, 138 via it associated terminals 168, 170. This raises thetemperature of the substrate 136 and, hence, the temperature inside theheating conduit 152.

Before, during, or after supplying current to the heating elements 136,138, the control unit 182 also operates the pump 120 to supply waterfrom the reservoir 114 to the heating elements 136, 138 via the conduits126, 128, 130, and the water enters the heating conduits 152 via theone-way valve 162. As the temperature of the water within the heatingconduits 152 is raised and the pressure inside the heating conduits 152increases, the water evacuates the heating conduits 152 into the filterbasket 104 via the showerhead 116. Once the heating conduits 152 havebeen at least partially evacuated, additional water is permitted to flowinto the heating conduits 152 via the one-way valve 162.

As shown in FIG. 3, because the illustrated holding tank 122 is elevatedin relation to the max-fill marker 134 of the reservoir 114 (and inrelation to the one-way valve 162), the holding tank 122 gravitationallypressurizing the water flowing from the reservoir 114 to the heatingdevice 124 to facilitate ensuring that water is supplied to the heatingelements 136, 138 despite whether the level of water within thereservoir 114 is low.

Optionally, in some contemplated embodiments (e.g., embodiments that donot include the pump 120), a flow control valve 186 may be disposedbetween the heating element(s) 136, 138 and the showerhead 116, as shownschematically in FIG. 9. In this manner, the flow control valve 186 maybe configured to prevent the heated water from prematurely evacuatingthe heating conduit(s) 152 until a predetermined water temperature isreached. For example, the control unit 182 may be configured to operatethe flow control valve 186 to inhibit the heated water from prematurelyevacuating the heating conduit(s) 152 until a predetermined watertemperature is reached. Thus, in some embodiments, the water may beheated to a desired temperature, which is selectable from a plurality ofpredetermined temperatures.

Referring now to FIGS. 10 and 11, rather than having heating device 124and showerhead 116, the fluid heating appliance 100 may instead have aheating device (indicated generally by reference numeral 188) andassociated showerhead 190. In the illustrated embodiment, the heatingdevice 188 includes a frame 192 (e.g., a silicone frame) and a pair ofthin-film heating elements 194 mounted in spaced relation on the frame192 such that the frame 192 substantially seals around the bottom andsides of each heating element 194.

The heating elements 194 are in the form of substantially rectangularpanes (e.g., are substantially planar objects), such that a heatingconduit 196 having an open-top, generally cuboidal volumetric shape isdefined between the heating elements 194. A one-way valve 198 isconnected to the frame 192 in flow communication with the bottom of theheating conduit 196, and the showerhead 190 is connected to the frame192 in flow communication with the open top of the heating conduit 196.The one-way valve 198 is also configured for connection to thedownstream conduit 130 to place the downstream conduit 130 in flowcommunication with the heating conduit 196 across the one-way valve 198.Optionally, in an alternative embodiment, the heating device 188 mayhave only one heating element 194, with an additional sidewall of theframe 192 in place of the other heating element 194, for example.

Each of the heating elements 194 is constructed much like the heatingelements 136, 138 above, in the sense that each heating element 194 hasa substrate, an electrically conductive material deposited on thesubstrate, and a pair of bus bars 199 suitably attached to, or depositedon, the substrate. When electrical current is supplied to the bus bars199 by the control unit 182, the current flows across the electricallyconductive material and heats the substrate to, in turn, heat theconduit 196. Water in the conduit 196 is heated as a result, and theheated water evacuates the conduit 196 toward the open top of theconduit 196 and spills over into the showerhead 190 for delivery to thefilter basket 104.

Moreover, the heating device 188 may be viewable through the window(s)112 of the housing 102, and may be illuminated by the light source(e.g., the LEDs 156), in a manner similar to that of heating device 124set forth above. Suitably, the control unit 182 operates the one-wayvalve 198 and the heating element(s) 194 in a manner similar to that setforth above for one-way valve 162 and heating elements 136, 138 (e.g.,to induce water flow into conduit 196, regulate the temperature withinconduit 196, etc.).

In accordance with the embodiments set forth herein, the coffeemaker 100having the heating device 124 and/or 188 heats water more rapidly and toa more precise temperature than at least some conventional calrod-typeheating devices, thereby improving the overall operating efficiency ofthe coffeemaker 100.

When introducing elements of the present invention or the preferredembodiment(s) thereof, the articles “a”, “an”, “the”, and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including”, and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:
 1. A coffeemaker comprising: a reservoir; and a flowcontrol system for regulating a flow of water from the reservoir,wherein the flow control system includes a thin-film heating elementthat defines at least a portion of a heating conduit in which water isheated.
 2. The coffeemaker of claim 1, wherein the heating element has aglass substrate and a metal oxide material deposited on the glasssubstrate.
 3. The coffeemaker of claim 2, wherein the heating element issubstantially transparent.
 4. The coffeemaker of claim 3, furthercomprising a housing in which the heating element is disposed, whereinthe housing has a window through which the heating element is visible.5. The coffeemaker of claim 4, further comprising a light source forilluminating water within the heating conduit.
 6. The coffeemaker ofclaim 5, wherein the light source emits a colored light.
 7. Thecoffeemaker of claim 5, wherein the heating element has an end andwherein the flow control system further comprises a one-way valveconnected to the heating element at the end, the light source beingmounted adjacent the one-way valve for emitting light into heatingconduit through the one-way valve.
 8. The coffeemaker of claim 1,wherein the heating element has an end and wherein the flow controlsystem further comprises a coupling fitted on the end to facilitateelectrically and thermally isolating the end of the heating element. 9.The coffeemaker of claim 1, further comprising a pair of the heatingelements.
 10. The coffeemaker of claim 9, wherein the heating elementsare spaced apart from one another and are oriented substantiallyparallel with one another.
 11. The coffeemaker of claim 1, wherein theheating element is substantially planar.
 12. The coffeemaker of claim 1,wherein the heating element is tubular and wherein the coffeemakerfurther comprises a first ring-shaped terminal and a second ring-shapedterminal that wrap around the heating element.
 13. The coffeemaker ofclaim 12, wherein the heating element has a first end and a second end,the first ring-shaped terminal wrapping around the heating element nearthe first end, and the second ring-shaped terminal wrapping around theheating element near the second end.
 14. The coffeemaker of claim 12,further comprising: a pair of the heating elements spaced apart from oneanother and oriented substantially parallel with one another; a firstterminal unit comprising a first bus bar and a pair of the firstring-shaped terminals connected together by the first bus bar; and asecond terminal unit comprising a second bus bar and a pair of thesecond ring-shaped terminals connected together by the second bus bar,wherein each of the first ring-shaped terminals wraps around one of theheating elements, and each of the second ring-shaped terminals wrapsaround one of the heating elements.
 15. A coffeemaker comprising: areservoir; a showerhead; and a flow control system for regulating a flowof water from the reservoir to the showerhead, wherein the flow controlsystem includes: a thin-film heating element that defines a heatingconduit in which water is heated; a check valve disposed between thereservoir and the heating element; and a flow control valve disposedbetween the heating element and the showerhead.
 16. The coffeemaker ofclaim 15, wherein the flow control system does not include a pump. 17.The coffeemaker of claim 16, wherein the flow control system isconfigured to gravitationally pressurize the flow of water from thereservoir to the showerhead.
 18. The coffeemaker of claim 17, whereinthe flow control valve inhibits heated water from prematurely evacuatingthe heating conduit until the heated water reaches a temperatureselected from a plurality of predetermined temperatures.
 19. Thecoffeemaker of claim 15, wherein the heating element is tubular andcomprises a glass substrate and a metal oxide material deposited on thesubstrate.
 20. A terminal unit for a heating device having a pair oftubular, thin-film heating elements, said terminal unit comprising: apair of ring-shaped terminals each sized to wrap around one of theheating elements; and a bus bar extending between the ring-shapedterminals to electrically connect the ring-shaped terminals to oneanother.